Fermentation is one obvious starting point for making chiral enantiomers, since it is a biological process and its products are therefore likely to be single-handed.

ECONOMIST: MONITOR

Moreover, if there are lots of chiral centres in a molecule, and each matters, the yield of the version with the right combination can be minuscule.

ECONOMIST: Inhuman genomes

Many organic molecules contain what are known as chiral centres.

ECONOMIST: Inhuman genomes

And Synthon Chiragenics, a drug-discovery company in Monmouth Junction, New Jersey, exploits carbohydrates such as lactose and starch abundant, freely available and notoriously chiral as building-blocks for more complex therapeutic drugs.

ECONOMIST: MONITOR